L’oro del fiume

Old gold-digger Boston Joe finds the treasure of three unscrupulous criminals and they kill him for it. But before he dies, he confess to Zagor where he hid the treasure, and asks him to find his nephew Robert, who was kidnapped by Indians ten years ago. And so Zagor, after sorting out the situation with the treasure, will go in search of the boy and the Fox tribe, who fell into the arms dealers' trap!

This story can be divided into two parts: 

First part of the story deals with the narrative line of the search for treasure and the conflict with three criminals.

Second part of the story is tied to the first part only by Zagor's promise to Boston Joe. The main actors, or villains, are two arms dealers, Harry Watson and his rough assistant Bryan. Unscrupulous traffickers duped Indians, convincing the warriors to barter the prized buffalo skins with the guns they stole from the Army.